Hoffman Criterion
The resulting failure index in Hoffman’s theory for an orthotropic lamina in a general state of plane stress (2D) with unequal tensile and compressive strengths is given by:
Findex=(1XT−1XC)σ1+(1YT−1YC)σ2+σ21XTXC+σ22YTYC−σ1σ2XTXC+τ212S2
Where:
- Xt,Xc are the maximum allowable stresses in the 1-direction in tension and compression,
- Yt,Yc are the maximum allowable stresses in the 2-direction in tension and compression,
- S is the allowable in-plane shear stress
Syntax
HoffmanFT(tensor,xt,xc,yt,yc,s,sets,plies,elems,parts,props,pool_name,layer_index,opt_str)
Arguments
- tensor
- Stress table
- xt
- Allowable tensile stress in ply material direction 1
- xc
- Allowable compressive stress in ply material direction 1
- yt
- Allowable tensile stress in ply material direction 2
- yc
- Allowable compressive stress in ply material direction 2
- s
- Allowable in-plane shear stress
- sets
- Set table (D=NULL)
- plies
- Ply table (D=NULL)
- elems
- Element table (D)
- parts
- Part table (D)
- props
- Property table (D)
- pool_name
- Pool name (D=@current_pool)
- layer_index
- Layer index (D=@current_slice_index)
- opt_str
- This is an optional argument, which can passed if needed (D=option).